Mediator and automation system

Abstract

A mediator has a mediator control unit (38) having an industrial Ethernet protocol module (381), at least one Ethernet APL protocol module (383, 384) and a compiler module (382) connected to the industrial Ethernet protocol module and to the at least one Ethernet APL protocol module, wherein the industrial Ethernet protocol module (381) interprets industrial Ethernet data provided via a first SPI interface and assigns them to industrial Ethernet services, wherein the at least one Ethernet APL protocol module (383, 384) interprets Ethernet APL data provided via a further SPI interface (40) and assigns them to Ethernet APL services, and wherein the compiler module (382) connects the industrial Ethernet services and the Ethernet APL services to one another and coordinates them in terms of time.

Description

[0001] Description

[0002] Intermediary and automation system

[0003] The patent application claims priority from German patent application 10 2023 109 608.7, the disclosure of which is hereby incorporated by reference.

[0004] The invention relates to an intermediary and an automation system with such an intermediary.

[0005] Modern concepts of industrial and process automation, i.e., the control and monitoring of technical processes using software, are based on the idea of ​​a central controller with a simultaneously distributed sensor / actuator level. A network, also referred to as a fieldbus system, connects field devices such as sensors and actuators to the central controller.

[0006] In order for the network participants, i.e. the field devices and the central controller, to be able to exchange messages via the fieldbus, a standardized protocol, hereinafter referred to as the fieldbus protocol, is used for message transmission between the participants, which specifies who (identifier) ​​outputs what (measured value, command) and when (initiative) on the fieldbus.

[0007] The most widely used standard for a network protocol is Ethernet, which allows message packets, also referred to as Ethernet telegrams, with payload data up to 1500 bytes in length to be transmitted at a transmission rate up to the gigabit / s range.

[0008] The Ethernet protocol was first used in office communication networks. Due to the advantages of the Ethernet concept, which arise from the use of standard hardware and software components and the ability to achieve high transmission rates even with simple networking technology, the Ethernet protocol has since become established in industrial and process automation.

[0009] Industrial and process automation uses a variety of fieldbus technologies that differ in terms of connection structure, bus access, and the Ethernet fieldbus protocol used. Therefore, many manufacturing plants require the integration of the fieldbus technologies into a common fieldbus solution.

[0010] In Ethernet-based fieldbus systems, the field devices are typically connected to the central controller via a switch with multiple connection interfaces, also referred to as ports. The switch can also transmit various Ethernet fieldbus protocols simultaneously. The switch determines which port an Ethernet telegram should be forwarded to based on the Ethernet address or the VI_AN tag provided in the Ethernet fieldbus protocols. Broadcast or multicast addresses are also possible, allowing the switch to forward an Ethernet telegram to multiple ports.

[0011] In a switch, it can be disruptive if Ethernet communication is delayed due to cross-traffic, additional services, uninterruptible telegrams, switch architecture, etc. Furthermore, an Ethernet telegram to be forwarded by the switch must always be at least 64 bytes long, even if a field device only wants to transmit a few bytes of user data cyclically.

[0012] Analog interfaces or fieldbuses such as I / O-Link or HART (Highway Addressable Remote Transducer) are typically used to directly connect sensors and actuators to the automation system. However, these have a limited transmission rate compared to Ethernet. With the advancement of digitalization and plant monitoring, however, the volume of data from sensors and actuators in the automation system is increasing, and this data must also be transmitted over long distances, especially in process automation.

[0013] With the Ethernet Advanced Physical Layer, also referred to as Ethernet-APL, the Ethernet standard IEEE 802.3 was extended to include a communication technology for long distances, which can use an intrinsically safe two-wire Ethernet cable, enabling a simple 2-wire connection of field devices.

[0014] In the OSI reference model, Ethernet-APL represents an extended physical layer (physical layer) for Single-Pair Ethernet (SPE), based on 10BASE-T1 L. Ethernet-APL can communicate at 10 Mbps, full duplex, over cable lengths of up to 1000 m. Ethernet-APL supports higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC-UA, and PROFINET. Fast, Ethernet-based fieldbus systems, also referred to as Industrial Ethernet, typically use twisted-pair cables with at least four wires as the physical layer for Ethernet telegram transmission for transmission rates exceeding 10 Mbps. In order to be able to combine components for 10 Mbit / s with components for more than 10 Mbit / s, for example 100 Mbit / s or 1 Gbit / s, intermediaries are used that enable protocol conversion between the different physical layers.

[0015] To utilize Ethernet-APL, the field devices used must fulfill additional features and functions. In addition to appropriate physical connectivity through plug-in or terminal connectors and features for compliance with explosion protection regulations, the field devices used also require additional or adapted software. Therefore, it is fundamentally desirable to be able to combine Ethernet-APL-capable field devices with conventional field devices.

[0016] The task is to provide an intermediary and an automation system with which Ethernet APL field devices can be easily integrated into an Industrial Ethernet fieldbus system.

[0017] The problem is solved with a mediator and an automation system according to the independent claims. Preferred developments are specified in the dependent claims.

[0018] A switch has a first connection interface for a first Ethernet media type, which is an industrial Ethernet with a transmission rate of more than 10 Mbps, and a first connection unit for the first Ethernet media type connected to the first connection interface. Furthermore, the switch comprises at least one second connection interface for a second Ethernet media type, which is an Ethernet APL (10 Base-T1 L) with a transmission rate of 10 Mbps on a single-pair Ethernet (SPE) cable, and a second connection unit for the second Ethernet media type connected to the at least one second connection interface.The switch also includes a switch control unit containing an Industrial Ethernet protocol module, at least one Ethernet APL protocol module, and a translator module connected to the Industrial Ethernet protocol module and the at least one Ethernet APL protocol module. A first SPI (Serial Peripheral Interface) interface connects the first connection unit to the Industrial Ethernet protocol module of the switch control unit, and a further SPI interface connects the second connection unit to the at least one Ethernet APL protocol module of the switch control unit. The first connection unit processes Industrial Ethernet data from Industrial Ethernet telegrams transmitted by the first connection interface and exchanges the Industrial Ethernet data with the Industrial Ethernet protocol module of the switch control unit via the first SPI interface.The Industrial Ethernet protocol module interprets the Industrial Ethernet data provided via the first SPI interface and assigns the Industrial Ethernet data to Industrial Ethernet services. The at least one second connection unit processes Ethernet APL data from Ethernet APL telegrams transmitted by the at least one second connection interface and exchanges the Ethernet APL data via the further SPI interface with the at least one Ethernet APL protocol module of the intermediary control unit. The at least one Ethernet APL protocol module interprets the Ethernet APL data provided via the further SPI interface and assigns the Ethernet APL data to Ethernet APL services. The translator module connects the Industrial Ethernet services and the Ethernet APL services with each other and coordinates the Industrial Ethernet services and the Ethernet APL services in terms of time.

[0019] The switch enables a central controller to transmit the user data for Ethernet APL field devices connected to the switch in a single Ethernet telegram. Neither a header nor a trailer, nor a minimum telegram size of 64 bytes, is required for each Ethernet APL field device. This saves telegram traffic and thus increases the performance of the automation system. In the switch, the two Ethernet media types are completely separated from each other by the interposed switch control unit. The switch control unit regulates the data exchange between the first connection interface, also referred to as the Industrial Ethernet port, and the second connection interface, also referred to as the Ethernet APL port, thereby achieving a high degree of determinism.The switch design thus prevents interference caused by cross-traffic, especially when multiple Ethernet APL ports are provided.

[0020] The translator module in the switch can have service filters that enable easy mapping between the Industrial Ethernet services of the Industrial Ethernet protocol module and the Ethernet APL services of the Ethernet APL protocol module. A firewall can be integrated into the translator module of the switch control unit to filter and / or prevent unwanted communication. This can improve security. All communication and services to the Ethernet APL field device run through the switch control unit and thus through the firewall. There is no way to reach the Ethernet APL field device via any other connection.

[0021] For Ethernet-APL communication to the Ethernet-APL field devices, a wide variety of higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC-11A, PROFINET, etc. can be used in the Ethernet-APL protocol module of the switchboard, which guarantees a high degree of flexibility.

[0022] An EtherCAT interface unit can be installed in the switchboard as the first interface unit, which processes the EtherCAT data from the Ethernet telegrams passing through the internal Ethernet terminal bus and makes it available to the switchboard control unit via the first SPI interface. The EtherCAT protocol is then used in the Industrial Ethernet protocol module. The switchboard thus forms an EtherCAT working node and also provides one or more Ethernet APL ports for the field level, to each of which one or more sensors or actuators can be connected.

[0023] The modular design of the switch as a terminal block ensures high port density and compact installation space. Integrating the switch into a terminal block housing enables modular and flexible integration of the Ethernet APL.

[0024] The multi-port terminal block offers the possibility of connecting Ethernet APL-capable field devices to an automation system that uses an Industrial Ethernet with transmission rates of more than 10 Mbit / s and uses twisted pair cables with at least 4 wires or rigid connections with at least 4 conductors for Ethernet telegram transmission as the physical layer.

[0025] With a terminal block that includes the intermediary as a terminal block, any terminal block can be operated, allowing signals from field devices to be acquired not only with Ethernet-APL as the physical layer, but also with other physical layers such as IO-Link or HART. Combinations with other terminal types are possible, ensuring easy integration into existing systems and modular expandability. In the automation system, the user data can be transmitted collectively from a server device as the central controller to the intermediary as the client device. Therefore, no header information is required in the Ethernet telegram for the individual field device, and thus no minimum Ethernet telegram size of 64 bytes is required. This saves data traffic and increases performance.

[0026] The automation system can include a bus terminal unit comprising a bus coupler and a number of terminal blocks, with the intermediary being a terminal block. Within the bus terminal unit, bus terminals with a wide variety of signal types, including Ethernet APL, can be connected in any order with the intermediary. It is also possible to replace individual bus terminals or subsequently expand the bus terminal unit.

[0027] The invention is explained in more detail below with reference to figures.

[0028] Fig. 1 shows an automation system with an intermediary.

[0029] Fig. 2 shows the schematic structure of the mediator in the automation system from Fig. 1.

[0030] Fig. 3 shows the schematic structure of the switch control unit of the switch from Fig. 2.

[0031] Fig. 4 shows a terminal block arrangement for use in the automation system from Fig. 1.

[0032] The figures are merely schematic and not to scale. Furthermore, the reference symbols in the figures remain unchanged when referring to elements or components of the same design.

[0033] In industrial and process automation, networks are used to connect distributed field devices at a sensor / actuator level to a central controller. Automation networks typically feature a serial bus, also referred to as a fieldbus, to which the network devices are connected. Manufacturers use various fieldbus concepts in automation networks, which differ in terms of the connection structure, bus access, and the standardized fieldbus protocol.

[0034] The fieldbus protocol defines how data exchange between the participants on the fieldbus is to be carried out. The fieldbus protocol determines the rules and formats for the participants' communication behavior. The fieldbus protocol typically has a layered architecture, with the individual protocol layers defined in the OSI reference model.

[0035] The message structure defined by the fieldbus protocol contains all information important for data exchange, such as the sender and recipient, message type, message size, and checksum for verifying error-free transmission. This information is prepended to the payload in the message as a header or appended as a trailer.

[0036] The Ethernet protocol has established itself as the communication standard for fieldbus systems. Within the framework of the OSI layer model, the Ethernet protocol defines the two lowest protocol layers: the physical layer, also referred to as the data link layer, and the data link layer. For data transmission in the higher protocol layers, standard communication protocols such as the TCP / IP protocol can be used within the Ethernet concept.

[0037] The Ethernet protocol divides the data to be transmitted into frames, also referred to as telegrams, whose structure is defined in the IEEE 802.3 standard. The Ethernet telegram is preceded by a preamble and a start bit, the so-called Start Frame Delimiter (SFD). This is followed by the actual Ethernet telegram. The Ethernet telegram consists of a header, a payload block, and a trailer.

[0038] The header begins with a 6-byte field for the destination address, followed by another 6-byte field with the source address. This can be followed by another 4-byte field, the so-called VLAN tag, with additional control data in the header, which primarily contains prioritization information. The header ends with a 2-byte field, the so-called type field, which provides information about the protocol used to process the data in the payload block. The payload block following the header can be up to 1500 bytes long, although larger data blocks are permitted in various Ethernet protocol extensions. The payload block is terminated by a variable-length field, the so-called PAD field, which guarantees the specified minimum length of 64 bytes for the Ethernet telegram.

[0039] The payload block is followed by the trailer, which contains a 4-byte field with a checksum. When an Ethernet telegram is created, a CRC calculation is performed on the bit sequence, and the checksum is appended to the data block. The receiver performs the same calculation after receiving the data. If the received checksum does not match the checksum it calculated itself, the receiver assumes an error in the transmission.

[0040] Real-time solutions based on the Ethernet protocol are also used in industrial and process automation. Real-time fieldbus systems based on the Ethernet standard include PROFINET, EtherCAT, Powerlink, and SERGOS III. The real-time protocol used to process the data in the payload block is displayed in the Type field in the header of the Ethernet telegram.

[0041] Fieldbus systems whose message transmission is based on the Ethernet protocol are often operated as server-client systems. The server device in the fieldbus system is the central controller, which has bus access authorization and can output data to the fieldbus. The client devices in the fieldbus system are the field devices, such as I / O devices, drives, transmitters, etc. They do not have bus access authorization and are only allowed to acknowledge received data and transmit data upon request from the server device.

[0042] In server-client systems, the server participant usually carries out control processes cyclically in order to generate output data for these and / or other client participants based on input data from client participants.

[0043] After completing a control process cycle, the server participant sends the output data in the form of Ethernet telegrams over the fieldbus. The client participants extract the output data assigned to the respective client participant from the Ethernet telegrams and use this output data to execute a local participant process. The data determined by the local participant process is then transferred from the client participant to the server participant and subsequently used by the server participant as input data for the next control process cycle.

[0044] When using the real-time EtherCAT protocol within a server-client system, the Ethernet telegrams are processed by the client devices in a single pass. Each client device on the fieldbus is assigned its own data block area in the payload area of ​​the Ethernet telegram.

[0045] Instead of a server-client configuration, a fieldbus system can also be operated using a provider-consumer model. In the provider-consumer model, each participant—that is, both the central controller and the field devices on the fieldbus—provides data that can be requested by one or more of the other participants. The data is provided cyclically. The real-time PROFINET protocol uses the provider-consumer model for Ethernet telegram exchange. The data in the payload area of ​​the Ethernet telegram is then intended for the consumer participant specified in the destination address.

[0046] Fast Ethernet-based fieldbus systems, also referred to as Industrial Ethernet, enable transmission rates of more than 10 Mbps using a twisted-pair cable with at least four wires as the physical layer. In automation systems, Industrial Ethernet is therefore used as fieldbus participants for Ethernet devices such as drives, flow meters, analyzers, and motor controllers that operate with at least four wires.

[0047] In order to be able to use the Ethernet standard even with 2-wire devices such as sensors and actuators, which are conventionally connected in the automation system via analog interfaces or fieldbuses such as I / O-Link or HART (Highway Addressable Remote Transducer) with a limited transmission rate, the Ethernet was developed with an Advanced Physical Layer, hereinafter referred to as Ethernet-APL.

[0048] Ethernet-APL is an extended physical layer for Single-Pair Ethernet (SPE) based on 10 BASE-T1 L, enabling communication at 10 Mbps in full-duplex mode over cable lengths of up to 1000 m. Ethernet-APL as a physical layer is capable of supporting EtherNet / IP, HART-IP, OPC UA, PROFINET, or other higher-level Ethernet protocols. Implementing Ethernet-APL in field devices requires adaptation of the device hardware with regard to the physical layer and of the device software with regard to the protocol stack. Therefore, it is desirable to continue to be able to integrate non-extended field devices into the automation system alternatively via analog interfaces or fieldbuses such as I / O-Link or HART.

[0049] In the switch, the two Ethernet media types are completely separated from each other by the interposed switch control unit. The control of data exchange between the first connection interface, also referred to as the Industrial Ethernet port, and the second connection interface, also referred to as the Ethernet APL port, is regulated by the switch control unit, achieving a high degree of determinism. The switch design thus prevents interference caused by cross-traffic, especially when multiple Ethernet APL ports are provided.

[0050] In order to connect Industrial Ethernet fieldbus systems, in which the participants exchange Ethernet telegrams at transmission rates of more than 10 Mbit / s, usually using a twisted pair cable with at least 4 wires for Ethernet telegram transmission as the physical layer, with Ethernet APL field devices that use a two-wire Ethernet cable with a transmission rate of 10 Mbit / s for communication, an intermediary is used that enables conversion between the different physical layers.

[0051] For this purpose, the switch has a first connection interface for the Industrial Ethernet with a transmission rate of more than 10 Mbit / s, hereinafter also referred to as the Industrial Ethernet port, and an Industrial Ethernet connection unit connected to the Industrial Ethernet port. Furthermore, the switch comprises at least one second connection interface for the Ethernet APL (10 Base-T 1 L) with a transmission rate of 10 Mbit / s on a Single-Pair Ethernet (SPE) cable, hereinafter also referred to as the Ethernet APL port, and an Ethernet APL connection unit connected to the Ethernet APL port.

[0052] The switch also includes a switch control unit which has an Industrial Ethernet protocol module, at least one Ethernet APL protocol module and a translator module connected to the Industrial Ethernet protocol module and the at least one Ethernet APL protocol module, a first SPI (Serial Peripheral Interface) interface which connects the Industrial Ethernet connection unit to the Industrial Ethernet protocol module of the switch control unit, and a further SPI interface which connects the Ethernet APL connection unit to the at least one Ethernet APL protocol module of the switch control unit.

[0053] The Industrial Ethernet interface unit processes Industrial Ethernet data from Industrial Ethernet telegrams transmitted from the Industrial Ethernet port and exchanges the Industrial Ethernet data with the Industrial Ethernet protocol module of the switchboard control unit via the first SPI interface. The Industrial Ethernet protocol module interprets the Industrial Ethernet data provided via the first SPI interface and assigns the Industrial Ethernet data to Industrial Ethernet services.

[0054] The at least one Ethernet APL connection unit processes Ethernet APL data from Ethernet APL telegrams transmitted from the at least one Ethernet APL port and exchanges the Ethernet APL data via the additional SPI interface with the at least one Ethernet APL protocol module of the switch control unit. The at least one Ethernet APL protocol module interprets the Ethernet APL data provided via the additional SPI interface and assigns the Ethernet APL data to Ethernet APL services.

[0055] The translator module connects the Industrial Ethernet services and the Ethernet APL services and coordinates the time between the Industrial Ethernet services and the Ethernet APL services.

[0056] The intermediary enables a server participant to transmit the payload data for the Ethernet APL field devices connected to the intermediary in a single Ethernet telegram, eliminating the need to provide a header or trailer for each Ethernet APL field device. The minimum telegram size of 64 bytes for Ethernet telegrams is also no longer required. This saves telegram traffic and thus increases the performance of the automation system.

[0057] In the switch, the two Ethernet media types are completely separated from each other by the interposed switch control unit. The switch control unit regulates data exchange between the Industrial Ethernet port and the Ethernet APL port, achieving a high degree of determinism. The switch design thus prevents interference from cross-traffic, especially when multiple Ethernet APL ports are planned. A firewall can be integrated into the translator module of the switch control unit to filter and / or prevent unwanted communication. This improves security. All communication between the server station and the Ethernet APL field devices takes place via the switch control unit and thus via the firewall.

[0058] For Ethernet-APL communication to the Ethernet-APL field device, a wide variety of higher-level Ethernet protocols such as EtherNet / IP, HART-IP, OPC-11A, PROFINET, etc. can be used in the Ethernet-APL protocol module of the switchboard, which guarantees a high degree of flexibility.

[0059] The mediator is explained below for an automation system in which the real-time capable EtherCAT protocol is used to interpret the data in the payload block of the Ethernet telegrams.

[0060] Figure 1 schematically shows the basic structure of the automation system with a server device 1, which forms the control level, and a client device 2, which represents the sensor / actuator level. The server device 1 and the client device 2 are connected via a serial fieldbus 3, which is designed here as an Industrial Ethernet fieldbus. The transmission medium can be, for example, a 4-wire twisted pair cable or a fiber optic cable. The representation of only one server device or only one client device in Fig. 1 is not to be understood as limiting. A plurality of server devices or client devices can always be connected to one another via the Industrial Ethernet network.

[0061] The use of the EtherCAT protocol in the automation system to interpret the data in the payload block of Ethernet telegrams is indicated in the Type field in the header of the Ethernet telegram. In principle, any known real-time or non-real-time capable fieldbus system can be used to process the data in the payload block of the Ethernet telegram.

[0062] In the automation system shown in Fig. 1, a network coupler 21 is provided in the client device 2 using the EtherCAT protocol. The network coupler 21 has an external interface 211 for connection to the serial fieldbus 3. The external interface 211 of the network coupler 1 is equipped with a receiving unit RX for receiving an Ethernet telegram from the transmission medium of the serial fieldbus 3 and a transmitting unit TX for transmitting an Ethernet telegram on the transmission medium of the serial fieldbus 3.

[0063] The network coupler 21 is further connected via an internal interface 212 to a series of EtherCAT devices 22, designated as EtherCAT units 22-1 to 22-n, via a ring-shaped transmission path 23. The ring-shaped transmission path 23 connects the EtherCAT units 22-1 to 22-n to form a ring topology. One or more EtherCAT units 22-1 to 22-n can act as intermediaries for connecting Ethernet APL field devices.

[0064] The ring-shaped transmission path 23 can have a simple and inexpensive 4-wire transmission physics based on Low Voltage Differential Signaling (LVDS) with a short range. To convert the Ethernet telegram from the transmission physics of the serial fieldbus 3 to the transmission physics of the ring-shaped transmission path 23, a coupler interface 213 is provided in the network coupler 21. This interface is arranged between the external interface 211 and the internal interface 212 of the network coupler 21.

[0065] The data transmission in the ring topology starts from the network coupler 21 and goes to the first EtherCAT unit 22-1 and from there to the last EtherCAT unit 22-n and then back to the network coupler 21.

[0066] An Ethernet telegram received by the network coupler 21 consists of the header with the receive identifier and the destination and source addresses, the payload area, and the trailer. The payload area provided between the header and the trailer contains the process data required for the control task, which preferably represents an entire process image. The process data is in turn grouped into data blocks required for the individual participants of the control task, i.e., for the first EtherCAT unit 22-1, "Data EtherCAT Unit 22-1," etc.

[0067] The Ethernet telegram sent by server participant 1 via serial fieldbus 3 containing the payload data for the individual EtherCAT units 22-1 to 22-n is received by the RX receiving unit of external interface 211 of network coupler 21. The received Ethernet telegram is then forwarded from external interface 211 to internal interface 212 in network coupler 21 after conversion from the transmission physics of serial fieldbus 3 to the transmission physics of ring-shaped transmission path 23 by coupler interface 213, with internal interface 212 then outputting the Ethernet telegram to ring-shaped transmission path 23 without any significant delay.

[0068] Each EtherCAT unit 22-1 to 22-n connected to the ring-shaped transmission path 23 then extracts data from the data block intended for the EtherCAT unit in the circulating Ethernet telegram or inserts data into the data block. The Ethernet telegram is then sent back to the internal interface 212 of the network coupler 21 after passing through the last EtherCAT unit 22-n.

[0069] The coupler interface 213 of the network coupler 1 converts the Ethernet telegram from the transmission physics of the ring-shaped transmission path 23 to the transmission physics of the serial fieldbus 3 and then forwards the Ethernet telegram to the external interface 211, which sends the Ethernet telegram with the transmission unit TX on the serial fieldbus 3 to the server participant 1.

[0070] The EtherCAT units connected to the network coupler are viewed by the Ethernet network as a single standard Ethernet node. Through the coupler connection in the network coupler, the Ethernet telegram received by the network coupler is output to the ring structure without any significant delay, allowing each EtherCAT unit to read data from the data block addressed to the respective EtherCAT unit in the Ethernet telegram while the Ethernet telegram is passing through the ring transmission path, or to insert data into the data block. The advantages of this approach are that, because the Ethernet telegram is processed during transit, no significant delays occur in data processing, thus ensuring the short response times required for real-time applications.

[0071] Fig. 2 shows a possible embodiment of one of the EtherCAT units 22-1 to 22-n in the automation system shown in Fig. 1 as an intermediary 30 for connecting Ethernet APL field devices.

[0072] The switch 30 has two first connection interfaces 31, which are designed here as a first EtherCAT port 311 and a second EtherCAT port 312 and which are connected to the ring-shaped transmission path 23. A first connection unit 33, which is designed here as an EtherCAT connection unit 331 and which processes the circulating Ethernet telegrams as it passes through, is connected between the two EtherCAT ports 311, 312 in the switch. The first connection unit 331 extracts data from the data block in the Ethernet telegram assigned to the switch 30 as the Ethernet telegram passes through the switch, or inserts data into the data block in the Ethernet telegram as the Ethernet telegram passes through the switch.

[0073] For the field level, the switch 30 has an Ethernet APL connection unit for each Ethernet APL port, which processes Ethernet APL telegrams from the assigned Ethernet APL port. Fig. 2 shows two second connection interfaces 34, which are designed here as a first Ethernet APL port 341 and a second Ethernet APL port 342. A second connection unit 36 ​​is each assigned to the two Ethernet APL ports 341, 342, which are designed here as a first Ethernet APL connection unit 361 and a second Ethernet APL connection unit 362. In principle, any number of Ethernet APL ports and associated Ethernet APL connection units can be provided. Ethernet APL field devices (not shown) are then connected to the individual Ethernet APL ports via a 2-wire cable.

[0074] Ethernet-APL interface units process Ethernet telegrams containing data from or for the Ethernet-APL field devices, which are received or sent via the assigned Ethernet-APL port. The Ethernet telegrams are processed using a higher-level Ethernet protocol implemented in the Ethernet-APL interface unit, which, in the described embodiment, is PROFINET.

[0075] The switch 30 also includes a switch control unit 38, which is connected to the EtherCAT connection unit via a first SPI (Serial Peripheral Interface) interface 39 and to the two Ethernet APL connection units 361, 362 via two further SPI interfaces 40, a second SPI interface 401 and a third SPI interface 402.

[0076] The mediator control unit 38 contains, as software modules, an Industrial Ethernet protocol module 381, a translator module 382, ​​hereinafter also referred to as a gateway module, and two Ethernet APL protocol modules, a first Ethernet APL protocol module 383 and a second Ethernet APL protocol module 384, each of which is assigned to an Ethernet APL connection unit. In the Industrial Ethernet protocol module 381, which is referred to here as an EtherCAT protocol module

[0077] 3811, the EtherCAT data blocks provided via the first SPI interface 39 are interpreted and divided into individual services. The two Ethernet APL protocol modules 383, 384 each interpret the Ethernet APL data provided via the second and third SPI interfaces 401, 402 and assign them to individual services. The gateway module 382, ​​arranged between the EtherCAT protocol module 3811 and the two Ethernet APL protocol modules 383, 384, connects the individual services and coordinates the timing of the services so that the services do not interfere with each other.

[0078] The switch control unit 38 is generally configured not to forward data between Ethernet APL ports. From the switch's perspective, the Ethernet APL ports are always physically completely separate.

[0079] Since all communication and services run through the gateway module, firewall functions can also be implemented there. Such a firewall unit 385 can also be integrated into the switchboard control unit 38 and, as shown in Fig. 2, be present as an additional software module.

[0080] In Fig. 3, the structure of the intermediary control unit 38 is shown in more detail, with the data flows between the software modules in the intermediary control unit 38 being shown.

[0081] The EtherCAT protocol module 3811 of the switchboard control unit 38 is equipped with an EtherCAT protocol stack. The EtherCAT protocol stack accepts the EtherCAT data blocks received from the EtherCAT interface unit via the first SPI interface, unpacks the EtherCAT data blocks, and forwards the EtherCAT data blocks containing data sorted according to the various configured services to the gateway module.

[0082] The first and second Ethernet-APL protocol modules 383, 384 of the intermediary control unit 38 are each provided with an Ethernet-APL protocol stack that uses the Ethernet-APL higher-level Ethernet protocol, PROFINET in the described embodiment. The Ethernet-APL protocol stack processes the payload data of the Ethernet telegrams received from the corresponding Ethernet-APL connection unit via the respectively assigned SPI interface and transfers the data to the gateway module sorted according to the various configured services. The gateway module 382 contains service filters assigned to the individual services. In the embodiment in Fig. 3, four service filters are provided: the control cycle service filter 382-1, the CAN over EtherCAT (CoE) service filter 382-2, the ADS over EtherCAT (AoE) service filter 382-3, and the Ethernet over EtherCAT (EoE) service filter 382-4. The service filters shown in Fig. 3 should not be understood as limiting.In principle, additional service filters can be provided. In particular, more or fewer service filters can be present.

[0083] The cyclic control data extracted from the EtherCAT data blocks contains Ethernet-APL port information, allowing the control cycle service filter 382-1 to send the corresponding data directly to the corresponding Ethernet-APL protocol module assigned to the Ethernet-APL port. The Ethernet-APL protocol module then packages the cyclic control data into an Ethernet telegram and forwards the Ethernet telegram via the assigned SPI interface to the corresponding Ethernet-APL interface unit, which outputs the Ethernet telegram on the Ethernet-APL port connected to the Ethernet-APL interface unit.

[0084] The CoE data extracted from the EtherCAT data blocks is acyclic data stored in various objects, including objects for configuring the Ethernet APL protocol modules. This defines which objects are used to configure the first Ethernet APL protocol module 383 and which are used to configure the second Ethernet APL protocol module 384, allowing the CoE service filter 382-2 to filter the objects and forward them directly to the corresponding Ethernet APL protocol module.

[0085] The AoE service is a freely definable acyclic service, which defines how acyclic Ethernet APL services are mapped to the AoE service. The mapping also includes address information that enables the AoE service filter 382-3 in the gateway module 382 to isolate the Ethernet APL ports and forward the data to the corresponding Ethernet APL protocol module. The Ethernet APL protocol module then packages the acyclic data into an Ethernet telegram and forwards the Ethernet telegram to the assigned Ethernet APL interface unit, which outputs the Ethernet telegram on the connected Ethernet APL port.

[0086] The EoE service tunnels Ethernet telegrams through the EtherCAT acyclic services, unpacks them, and forwards the Ethernet telegrams to the EoE service filter 382-4. The EoE service filter 382-4 can then filter out the Ethernet APL port based on the destination address contained in each Ethernet telegram and sends the Ethernet telegram directly to the assigned Ethernet APL interface unit, bypassing the Ethernet APL protocol modules.

[0087] When sorting the payload data of the Ethernet telegrams received via the respectively assigned SPI interface from the corresponding Ethernet APL interface unit by the first and second Ethernet APL protocol modules 383, 384 of the mediator control unit 38, the service filters do not have to perform any port assignment, since only a single EtherCAT interface unit is provided.

[0088] The firewall unit 385 is connected to the gateway module 382 and can check the data flows of all service filters based on security specifications and then block a corrupted data flow if necessary.

[0089] A data flow from server participant 1 to an Ethernet APL actuator (not shown) connected to the first Ethernet APL port 341 would be performed as follows.

[0090] The actuator control data is generated by server device 1 as part of a control process and packaged into an EtherCAT data block of an Ethernet telegram. Server device 1 then sends the Ethernet telegram to client device 2 via serial fieldbus 3.

[0091] The network coupler 21 of the client subscriber 2 then converts the Ethernet telegram from the transmission physics of the serial fieldbus 3 to the transmission physics of the ring-shaped transmission path 23 and subsequently outputs the Ethernet telegram on the ring-shaped transmission path 23.

[0092] The mediator 30 processes the circulating Ethernet telegrams in transit with the EtherCAT interface unit 331. The EtherCAT interface unit 331 extracts the EtherCAT data block from the Ethernet telegram and forwards the EtherCAT data block via the first SPI interface 39 to the EtherCAT protocol module 3811 of the mediator control unit 38.

[0093] The EtherCAT protocol stack in the EtherCAT protocol module 3811 extracts the actuator control data and forwards the actuator control data to the control cycle service filter 382-1 in the gateway module 382. The actuator control data extracted from the EtherCAT data block contains Ethernet APL port information, so the control cycle service filter 382-1 forwards the data directly to the first Ethernet APL protocol module 383, which is assigned to the first Ethernet APL port 341.

[0094] The first Ethernet-APL protocol module 383 then packages the actuator control data into an Ethernet telegram and forwards the Ethernet telegram via the associated second SPI interface 401 to the first Ethernet-APL connection unit 361, which outputs the Ethernet telegram on the first Ethernet-APL port 341 connected to the first Ethernet-APL connection unit 361, to which the Ethernet-APL actuator is connected.

[0095] By designing the switch 30 as a terminal block, a high port density and a compact installation space can be achieved. Furthermore, integrating the switch as a terminal block into a bus terminal unit enables a modular and flexible implementation of the Ethernet APL.

[0096] A bus terminal unit consists of a bus coupler and a large number of electronic terminal blocks. The bus coupler has a fieldbus interface, thus connecting the bus terminals to the central controller. Bus couplers can be equipped with their own intelligence and, in small-scale applications, have PLC functionality to process smaller control tasks decentrally, without intervention from the central controller.

[0097] The bus coupler corresponds to the Ethernet coupler 21 shown in Fig. 1 and serves as the link between the Ethernet protocol at the fieldbus level and the terminal blocks. Communication between the bus coupler and the individual terminal blocks then takes place via an internal Ethernet terminal bus, which connects the terminal blocks wirelessly via contacts.

[0098] The bus coupler converts the transmission physics of the fieldbus level and the terminal block level without changing the process data stream. For example, the bus coupler converts Ethernet telegrams from an Ethernet 100BASE-TX physics on the fieldbus to the internal Ethernet terminal bus. The internal Ethernet terminal bus is also transmitted at 100 Mbps, but has a more cost-effective physical layer based on Low Voltage Differential Signaling (LVDS). The bus terminal unit is mounted in a control cabinet, usually on a DIN rail. Bus terminals with a wide variety of signal types can be arranged in any order within the bus terminal unit. Replacing individual bus terminals or subsequently expanding the bus terminal unit is also possible within the system's physical limits.

[0099] Bus terminal units can be used wherever analog and digital inputs and outputs (I / Os) need to be wired and transmitted to a central controller via a fieldbus. Bus terminal units make it possible to bundle the multitude of different sensor signals and forward them to the central controller via a uniform bus signal, or to forward commands from the central controller to the actuators.

[0100] By using intermediaries in the form of terminal blocks within a bus terminal line, it is possible to transfer signals from sublevels that communicate via an Ethernet APL to the higher-level fast industrial Ethernet fieldbus.

[0101] Fig. 4 shows a bus terminal unit 400 in which the switch 30 is integrated as a terminal block. The bus terminal unit 400 has, as its first module, a bus coupler 410, which may include a slot 411 for a bus cable (not shown). Slot 411 may, for example, be configured as an RJ45 socket to accommodate an RJ45 plug of the bus cable. Furthermore, the bus coupler has several DIP (Dual In-Line Package) switches 412, for example, to set an address. Furthermore, several LEDs 413 are arranged on the bus coupler to indicate an operating state of the bus coupler.

[0102] Seven terminal blocks 420 are connected to the bus coupler 410 in Fig. 4, with the fifth terminal block being the switchover module 30. The number of terminal blocks shown in Fig. 4 is not intended to be limiting. In particular, more or fewer terminal blocks can be provided. Thus, a bus terminal unit can be designed with up to 255 terminal blocks.

[0103] The terminal blocks 420, including the switch 30 in Fig. 4, are identically constructed and have two opposite outer sides, each of which has contact arrangements for communication and power supply. The design of the terminal blocks, particularly with regard to the terminal width, can vary.

[0104] The front of the terminal blocks features cable connection devices for directly connecting sensors and actuators or subordinate fieldbus systems. The terminal blocks 420 shown in Fig. 4 feature four 2-wire connection devices 421 per terminal block, arranged one above the other. However, the terminal blocks can also be equipped with different connection options.

[0105] Furthermore, several LEDs 422 are arranged on the front of the terminal block to indicate the operating status of the terminal block. The individual terminal blocks 420 are plugged together and snapped onto a DIN rail 430. The DIN rail 430 can be mounted, for example, using screws in a control cabinet (not shown here).

[0106] List of reference symbols

[0107] 1 server participant

[0108] 2 client participants

[0109] 3 serial fieldbus

[0110] 21 network couplers

[0111] 211 external interface

[0112] 212 internal interface

[0113] 22 EtherCAT participants

[0114] 22-1 to 22-n EtherCAT unit

[0115] 23 ring-shaped transmission path

[0116] 213 Coupler connection

[0117] 30 intermediaries

[0118] 31 first connection interface

[0119] 311 first EtherCAT port

[0120] 312 second EtherCAT port

[0121] 331 EtherCAT connection unit

[0122] 34 second connection interface

[0123] 341 first Ethernet APL port

[0124] 342 second Ethernet APL port

[0125] 36 second connection unit

[0126] 361 first Ethernet APL connection unit

[0127] 362 second Ethernet APL connection unit

[0128] 38 Intermediary control unit

[0129] 381 Industrial Ethernet protocol module

[0130] 3811 EtherCAT protocol module

[0131] 382 Translator Module

[0132] 382-1 Control Cycle Service Filter

[0133] 382-2 CoE Service Filter

[0134] 382-3 AoE Service Filter

[0135] 382-4 EoE Service Filter

[0136] 383 first Ethernet APL protocol module

[0137] 384 second Ethernet APL protocol module

[0138] 385 Firewall Unit

[0139] 39 first SPI interface

[0140] 40 additional SPI interfaces

[0141] 401 second SPI interface 402 third SPI interface

[0142] 400 Bus Terminal Unit

[0143] 410 Bus Coupler

[0144] 411 slot

[0145] 412 DIP switches

[0146] 413 Bus coupler LED

[0147] 420 terminal blocks

[0148] 421 2-wire connection device

[0149] 422 terminal block LED

[0150] 430 DIN rail

Claims

Claims 1. A switch comprising a first connection interface (31) for a first Ethernet media type, which is an Industrial Ethernet with a transmission rate of more than 10 Mbit / s, a first connection unit (33) for the first Ethernet media type connected to the first connection interface, at least one second connection interface (34) for a second Ethernet media type, which is an Ethernet APL (10 Base-T1 L) with a transmission rate of 10 Mbit / s on a Single-Pair Ethernet (SPE) cable, at least one second connection unit (36) for the second Ethernet media type connected to the at least one second connection interface, a switch control unit (38) comprising an Industrial Ethernet protocol module (381), at least one Ethernet APL protocol module (383, 384), and a translator module (382) connected to the Industrial Ethernet protocol module and the at least one Ethernet APL protocol module. has,with a first SPI (Serial Peripheral Interface) interface (39) connecting the first connection unit (33) to the Industrial Ethernet protocol module (381) of the intermediary control unit (38), with a further SPI interface (40) connecting the second connection unit (36) to the at least one Ethernet APL protocol module (383, 384) of the intermediary control unit (38), wherein the first connection unit (33) processes Industrial Ethernet data from Industrial Ethernet telegrams transmitted from the first connection interface and exchanges it with the Industrial Ethernet protocol module of the intermediary control unit via the first SPI interface, wherein the Industrial Ethernet protocol module (381) interprets the Industrial Ethernet data provided via the first SPI interface and assigns it to Industrial Ethernet services,wherein the at least one second connection unit (36) processes Ethernet APL data from Ethernet APL telegrams transmitted from the at least one second connection interface and exchanges them via the further SPI interface with the at least one Ethernet APL protocol module of the switch control unit (38), wherein the at least one Ethernet APL protocol module (383, 384) interprets Ethernet APL data provided via the further SPI interface (40) and assigns it to Ethernet APL services, and, wherein the translator module (382) interconnects and time-coordinates the Industrial Ethernet services and the Ethernet APL services.

2. The intermediary of claim 1, wherein the translator module (382) comprises service filters (382-1, 382-2, 382-3, 382-4) associated with the services.

3. The intermediary of claim 1 or 2, wherein the intermediary control unit (38) comprises a firewall (385) to filter and / or prevent unwanted communication.

4. Switch according to one of claims 1 to 3, wherein a higher-level Ethernet protocol is used in the Ethernet APL protocol module (383, 384) of the switch (30).

5. A switch according to any one of claims 1 to 4, wherein the first connection unit is an EtherCAT connection unit (33), and wherein the EtherCAT protocol is used in the Industrial Ethernet protocol module (381).

6. Switch according to one of claims 1 to 5, wherein the switch (30) is designed as a terminal block (420), in particular as a multi-port terminal block.

7. Automation system with a server participant (1) and an intermediary according to one of claims 1 to 6 as client participant (2).

8. Automation system according to claim 7, wherein a bus terminal unit (400) is provided which has a bus coupler (411) and a number of terminal blocks (420), wherein the intermediary (30) is a terminal block.

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